The present invention relates to bridges. More particularly, the present invention relates to computing devices with bridges.
Computing devices, for example, personal computers, laptops and smart phones, are widely used in everyday life. To access data stored in a computing device (a master device, hereinafter “the master”), a peripheral device (a slave device, hereinafter “the slave”), for example, a media player, a universal serial bus (USB) drive or a portable hard disk, may be connected in a wired or wireless fashion to the master through a communication port built in or local to the master. Examples of the communication port may include a USB port (either A-type or B-type), an “Institute of Electrical and Electronics Engineers” (IEEE) 1394 port, a “Peripheral Component Interconnect” (PCI) Express port or a “Serial Advanced Technology Attachment” (Serial ATA; SATA) port. Data communications between the master and the slave may be established with the help of protocols related to the communication ports. For example, a slave such as a USB device may communicate with a master such as a computer by converting data to be transferred into “non return to zero, inverted” (NRZI) signals and then transfer the signals through the “D−” and “D+” ports at the USB device.
The above-mentioned method for data communications between a master and a slave may no longer be useful for data communications between two masters. For example, both of the masters may compete with one another for the role of a master device during data communications when the two masters are coupled together. Consequently, data communications may not be established, which in turn may incur system failure, abnormal end of task (ABEND) or malfunction of the computing devices.
Moreover, with the increasing interest in compact, low-profile and light-weight electronic products, some computing devices may be designed with an economic number of embedded function devices or modules. For example, some computing devices may not include embedded storage media such as a CD-ROM (i.e., a CD-R or CD-RW) or a DVD-ROM (i.e., a DVD-R or DVD-R/W). Furthermore, some may only include a small storage volume (e.g., a small hard disk) which may not be large enough for certain applications. When using such computing devices, users may not have enough functions (e.g., storage media or volume) to use. It may therefore be desirable to have an external device such as a bridge to allow a computing device to use the functions or resources of another computing device without incurring the competition issue.